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Irish Mythology for Beginners

Irish mythology is a large body of stories about gods, heroes, kings and the Otherworld, written down by Christian monks in the Middle Ages from much older oral tradition. It is not one story. The tales are grouped into four cycles, and most of the famous names belong to one of them. This guide gives you the map, with links into the sourced entry for each name.

The four cycles

The Mythological Cycle is the oldest, telling of the divine race known as the Tuatha Dé Danann and the successive invasions of Ireland. The Ulster Cycle follows the court of King Conchobar mac Nessa at Emain Macha, centred on Cú Chulainn and the cattle raid of the Táin Bó Cúailnge. The Fenian Cycle tells of Fionn mac Cumhaill and his warrior band, the Fianna, in a world of hunting, romance and adventure. The Historical Cycle, also called the Cycle of the Kings, gathers legends of Ireland's High Kings that medieval scribes treated as national history.

The gods: Tuatha Dé Danann

The Tuatha Dé Danann, "the people of the goddess Danu", are the divine race of Irish mythology. Their chief is the Dagda, associated with abundance, wisdom and strength. Their first king, Nuada, loses an arm in battle and is given one of silver. Lugh, a master of many skills, kills the Fomorian tyrant Balor in the battle recounted in Cath Maige Tuired.

Other major figures include Brigid, goddess of poetry, healing and smithcraft; the Morrígan, a goddess of war, fate and sovereignty who appears as a crow; Manannán mac Lir, god of the sea and the Otherworld; Aengus, god of love and youth; Ogma, credited with inventing the Ogham alphabet; and Dian Cécht, the healer. Their enemies are the Fomorians, a race of hostile, otherworldly beings.

The heroes

In the Ulster Cycle, Cú Chulainn is the central hero. Around him are Medb, the warrior-queen of Connacht, and her husband Ailill; Ferdiad, his foster-brother forced to fight him; Scáthach, who trains him; and Deirdre and Naoise, whose flight from Conchobar is one of the great tragedies. In the Fenian Cycle, Fionn leads the Fianna with Oisín, Oscar and Diarmuid, whose flight with Gráinne becomes a famous love story.

Places and the Otherworld

The Hill of Tara was the ceremonial seat of the High Kings, and Uisneach is traditionally the sacred centre of Ireland. Newgrange in the Boyne Valley is tied to the Dagda and his son Aengus, and Cruachan is Medb's royal seat. Beyond the mortal world lies Tír na nÓg, the Land of the Young, where time runs differently.

Festivals

The Irish year was marked by four festivals: Samhain, the start of the dark half of the year when the boundary with the Otherworld grows thin; Imbolc, the first stirrings of spring, sacred to Brigid; Bealtaine, the start of summer; and Lúnasa, the harvest festival founded by Lugh. You can also read the Samhain guide.

Folklore creatures

Alongside the myths sits a large body of folklore: the banshee, whose keening foretells a death; the púca, a shape-shifting trickster; the dullahan, a headless rider; the leprechaun; the merrow; and the Sluagh, a host of restless dead.

Where the stories come from

No myth was written down in the pagan period. The stories survive in medieval manuscripts such as Lebor na hUidre, Ireland's oldest surviving manuscript written entirely in Irish, and in compilations like Lebor Gabála Érenn, the Book of Invasions, and Acallam na Senórach, the main source for the Fenian Cycle. The versions we read were shaped by monastic scribes, so different texts often disagree. Each entry on this site names its sources so you can check them.

Where to go next

If you only read three entries, start with the Dagda, Cú Chulainn and Fionn mac Cumhaill. Or explore every entry on the browse page, trace how figures are related in the family tree, or write your name in the old Irish script with the Ogham name converter. If you are curious how Irish names carry these old stories, NameCipher has the meanings and origins of Irish names.